Latch device



June 4, 1929. w, A, SMITH A 1,715,793

LATCH DEVICE Filed July 6, 1926 2 Sheets-Sheet 1 I hij June 4, 1929.4 w.A. sMlTH 1,715,793.

LATCH DEVICE Filed July 5, 1926 2 Sheets-Sheet 2 Patented June 4, 1929.

UNITED STATES PATENT FFICE. 'l

WALTER ADAM SMITH, OE BELVIDERE, ILLINOIS, ASSIGNOR TO NATIONAL SEWINGMACHINE COMPANY, OF BELVIDERE, ILLINOIS, A CORPORATION OFILLINOIS.

'LATCH This invention relates to bib locking de-v vices, intended moreparticularly for locking the bib device of a sewing machine cabinet;although it is not restricted to such use and may be used in connectionwith typewriter cabinets, and otherwise.

In sewing machines, the. operative mechanism is provided with a metalbase plate pivotally or hingedly mounted at the margin of an opening` inthe top of' the cabinet andV designed so that the mechanismmay be swungbelow the surface of the cabinet when not in use, and may be raised tothe surface of the table for use. To hold it in raised position,

' the cabinet is provided with a hinged section of table top, commonlyknown in the trade as a bib. A portion of the machine base rests upon aportion of the bib, and when so positioned for operation, the motion ofthe machine parts produces considerable vibration, whereby the bib isshaken and rattled.

In an attempt to remedy this objection, locking devices have been usedon the base of the machine to lock said base to the bib. Such lockingdevices may comprise a latch device to engage a suitable projection onthe bib. Notwithstanding; the use of a locking device between themachine base and bib, the vibratory motion of the machine parts producesrelative movement not only between the machine and the cabinet but alsobetween the bib and the cabinet, which is Vdetrimental to the sewingmachine as a whole and unpleasant for the operator o the machine.

It is desirable, therefore, to provide, in addition to the base and biblatching device, a

locking device between the bib and cabinet proper.

The principal object of my invention, therefore, is to produce ar deviceby which the bib will normally be unlocked from the cabinet, so as to beswingingly movable with respect to the cabinet table top, when themachine is being moved into and out off operative position; and whichwill be automatically operated into a position to loclr the `bib to thecabinet by the act of the machine base being brought into operativeposition upon the bib.

YAnother object of the invention is to pro- DEVICE.

Serial No. 120,697.

vide a bib locking device which will be automatically actuated into itslocked position by means upon the sewing machine base and which willautomatically assume an unlocked position upon withdrawal of said means.

Another object of' the invention is to provide a bib locking device socorrelated in its e position and in its action to a machine base lockingdevice, as to supplement the action of each other, and which willoperate simultaneously with the machine locking device in effecting thelocking action between thebib and cabinet. v

These and other objects of the invention will be more fully understoodby reference to the accompanying` drawings in which I have shown oneform of device embodying the principle of the invention.`

In the drawings:

Figure l is a top or plan view of a sewing machine in position upon thetop ot a cabinet, the latter being` partially broken away, with the biblock oit my invention indicated in dotted lines.

Figure 2 is a yvertical sectional view through the bib of the sewingmachine cabinet,-with my locking device shown in elevation. y

Figure 3 is a vertical sectional view through the bib and the top ofthe' cabinet table, with the machine' base raised.

Figure 4L is a plan view of a portion of the table top and of the bib.

Figure is a detail view, enlarged, showing the actuating member on themachine, engaged with the locking bolts ot the device; the bolts beingin the unlocked position.

Figure 6 is a view similar to Figure 5, with the bolt ends spread apartor in locked position. t

Referring to the drawings, A represents a sewing machine cabinet, inpart, provided with a table-top l, which is centrally apen tured asindicated at 2, whereby a machine base B hingedly secured along one ofits side margins to the table top i, as indicated at 3, may be swunginto a pocket i located below the table top l, when the machine is notin use, and through which recess 2 the machine may be liftedoutofthe-pocket and then brought to proper operative position with relationto the table top, in a well known manner.

To the side of the aperture 2, opposite that to which the sewing machinebase is pivotally or hingedly mounted, is what is known in the trade asthe bib C, which latter is likewise swingingly mounted so as to beraised above the surface of the table top 1 when the machine B is beinglifted out of the pocket l and to swing downwardly into normal positionwith its top surface t3 in the same hori Zontal plane as the top surface1 of the table, and there to engage the machine base B when the latteris brought down into its operative position. The upper edge of theswinging bib C is rabbeted so as to form a shoulder support 6 for theedge 7 of the machine base B; the machine being thus held in itsoperative position by the shoulder support 6 along one of its edges andby the hinged connection 3 along its opposite edge.

To lock the machine base and the bib C together, I provide on the lowerside of the bib, a fiat bar or plate 8, the end of which projects beyondthe inner edge 9 of the bib C, `as clearly shown in Figures 3 and 4.Upon the machine base E I provide a swinging lever 10 pivotally mountedat 11 to the base and carrying on one arm a latch 12 adapted forengagement with the bar 8.V The lower edge of the latch 12 is curved sothat when the machine B is being moved into operative position, thisrounded edge acts with the familiar latch action and its hook orshoulder portion 13 is brought into locking engagement with the bar 8,as clearly illustrated in Figures andb. A tension spring lll keeps thelatch lever in proper operative position when disengaged from the bar Hand promptly returns itr to that position as the hooked shoulder 13 ismoved out from under the bar 8.4 This movement is accomplished by reasonof the fact that the short arm 15 of thelever 10 is pivotally attachedat 16 to a vertically movable push button 17. The button 17 is mountedthrough the machine base B with its upper portion projecting so as to bein convenient position to be depressed by the operator when thelatterdesires to disengage the hooked lever 10 from the bar 8. This isall familiar practice and my invention is not to be limited to theparticular form or shape of the means just described for locking thebase to the bolt 8 on the bib.

N ear this locking device, however, T secure to a. flange 18 on themachine base B, an actuating member 19, b y means of a screw bolt 20,011any other convenient means. The function and purpose of this actuatingmember 19 will presently be described.

Upon the under surface 21 of the bib C, I provide a plurality7 ofapertured bearing plates or members indicated at 22, the aperturesthereof being in alignment and parallel with the side edge 9 of the bib.These bearing plates 22 are spaced apart in groups, one group arrangedto accommodate a bolt bar D and the other group to support a bolt E. Thebolts D and E may be of any convenient form in cross section but lprefer, and have herein `shown these bolts to be square in crosssection, as clearly indicated. Tt follows that the bearing openings inthe supports 22 for these bolts must be complementally shaped so thatthe bars or bolts D and E may be moved longitudinally through thebearing plates 22. As a matter of convenience, I have made the bolts Dand E of vdifferent lengths but this is Ynot essential to the invention,as will pres ently appear. The bolts -D and E are bent between theirends so as to present an inwardly turned arm 23 on the bar D and an arm24 on the bar E. These arms 23 and 2a are spaced apart, are parallel toeach other and are sufficiently close together so that the lowlerportion of the actuating member 19 of the plate B, when the machine isbeing lowered into its operative position, will be entered into thespace between the two arms 23 and 24, and as the lowering continues,push further into saidv space and spread said arms 23 and 24e apart.This movement imparts a lon gitudinal movement to the bolts D and E,through their respective bearing plates 22,

and in opposite directions. Moreover, this Y movement of the bolts D andE will be of such extent as to cause the eXtreme end 25 of the bar D andthe extreme end 26 of the bar E to project beyond the respective lsidemargins 27 and 2S of the bib C, as shown in Fig ure 2.

This spreading apart of the bolts D and E is accomplished, as will beunderstood by reference to Figures 5 and 6, by means of the actuatingmember 19, provided with converging side margins 29, which exert awedging action between the two arms 23 and 2a to spread them apart.l/Vhen so spread apart, the ends 25 and 26`of the bolts D and E,respectively, will engage the under side of the top 1 of table A andthus securely lockthe bib C to the table A.

Surrounding the bolt D is a 'tension spring 30, one end of which bearsagainst the surface of a bearing plate 22 and the other end against apin 31 in the bolt D. Thus as the bolt D is moved outwardly the spring30 is put under tension and as soon as the actuating` member 19 is movedaway from the arnr23 of said bolt, the spring 30 expands and promptlyreturns the bolt D to its original position shown in Figure e. The boltE is similarly provided with a spring 82, one end of which bears againstthe pin 33 on the bolt E and the other end of which bears against thebearing plate 22. The act-ion of the bolt E and spring 32 is the same asust explained with reference tothe bolt D and spring 30.

To prevent the springs 30 and 32 from driving the bolts D and E fromtheir locked position, as shown in Figure 2, beyond their' properlyunlocked position'as shown in Figure 4, the bolt D is provided with astop pin 34 adapted to contactwith a bearing plate 22 and the bolt'E isprovided with a stop pin 35 adapted to contact with another bearingplate 22.

The relative length of the bolts D and E is not important, it-beingessential only that their respeetivearms 23 and 24 be located at suchpoint as to be in operative position with respect to the location of theactuating member 19.

It will be noted that when the machine base B is in. a raised position,as iter example, that indicated in full lines in Figure 3, and is thenlowered to its operative position as indicated in dotted lines in Figure3, the locking device will operate automatically; that is to say, thebase latch 10 will engage the bar S' on the bib C and the actuatingmember 19 will spread apart the bars D and E so that their respectiveouter ends will lock in and engage the under surface of the table. theparts will thus be firmly locked together .in operative position andwill remain so locked until suoli time as the actuating' member 17 ismanually operated against the tension of the spring 14 to cause thehooked part 12 to become disengaged or unlatehed from the bar 3. Thenand then only may the machine be swung out ot' its operative position,thereby withdrawing the actuating member 19 from between the arms 23 and24 and permitting the springs o0 and 32 to expand and move the bolts Dand E to their normal positions.

It will be noted that the locking functions are performedsimultaneously, but that before the unlocking of the bib C from thetable A may be accomplished, it v'ill first be necessary to unlock themachine B from the bib C. rlhis inter-relation of the two locking partscontributes to the utility of thedevice as a whole in machines ol thecharacter described, in that great steadiness and lirmness is producedand vibration greatly reduced. Furthermore, this arrangement preventsdamage to the cabinet resulting from the operator attempting to lift themachine base from the bib without iirst properly unlocking the machinebase lock.

I claim as my invention:

1. A. device of the class described, comprising a iixed support and amovable support hinged thereto, a base member hinged to said fixedsupport and having means adapted to interlock with said movable support,a pair of bolt bars mounted on the movable support adjacent thatlongitudinal margin opposite the hinged margin, said bolt bars beingmovable in opposite directionsand adapted to engage the fixed support,and means rigidly secured adjacent the free margin of the base Allymember in position. to automatically actuate said bolt bars when saidbase member is movedl into juxtapositionto said movablesupport. j

.2'. A device comprising a lixed support having two independentlymovable elements oppo'sitely hinged thereto, a pair of bolt bars movablymounted upon one hinged element near that longitudinal margin oppositethe hinged margin, said bolt bars being movable in opposite directionsand adapted to engage the iixed support, and means rigidly secured tothe free margin of the other hinged element in position ytoautomatically actuate said bolt bars when said second hinged element ismoved into juxtaposition to said first hinged member, said'boltbarsbeing Aprovided on their proximate ends with bent arms parallel toeach other, and said actuating means being provided with taperedsurfaces for engaging said arms.

3. A disappearing -instrument comprising a iixed support having twoindependently movable elements oppositely hinged thereto, a pair of boltbars movably mounted upon one hinged element near that longitudinalmargin opposite the hinged margin, said bolt bars being movable inopposite directions and adapted to engage the fix-ed suppe-rt, meansrigidly secured to the free margin of the other hinged element inposition to automatically act-nate said bolt bars When said secondhinged element is CII cabinet moved into juxtaposition to said firsthinged i member, said bolt bars being provided with means for retractingthe bars from latching engagement with the fixed support when the boltbar actuating means is withdrawn, and means for locking said oppositelyhinged members together.

4. In a drop head sewing machine cabinet, a fixed support, a supporthinged to said fixed support, a machine base hinged to said ixed supportand having means adapted to interlock with said hinged support, a pairof spaced apart bolt bars movably mounted on the underside of'saidhinged support and having` their proximate ends bent outwardly toproject beyond the free margin of said hinged support, the other endsvofsaid bolt bars being adapted to engage said fixed support, and meansrigidly secured to the under side olf the machine base in position tocontact with said projecting bolt arms to automatically spread themapart when said machine base is lowered to the plane of said hingedsupport.

5. A device of the class described, comprising a lixed support and amovable support, a member hinged to said iixed support and having meansadapted to interlock with said movable support, and means operable bythe movement of said member to interlocking position for interlockingsaid fixed and movable supports.

6. A disappearing-instrument cabinet, comprising a fixed support und a`support hinged to said iixed support, an instrument base hinged te saidfixed support and having means adapted t0 intei'loek with said hingedsupport, normally inoperative means Carried by said hinged support andadapted te intei-n lock with said iixed support, and means ein iied bySaid instrument. base for automatically actuating said last mentionedmeans 10 prior to the interlocking of said instrument hase and hingedsupport.

In testimony, that l Claim the foregoing as my inventionl aiiix mysignature this lst day of July, 1925.

TALTER ADAM SMTI-.

